1. Field
The present invention relates to a drop mass deviation measuring apparatus, a drop mass deviation measuring method of the same, a pattern forming system using the same, and a control method of the pattern forming system using the same, and, more particularly, to a drop mass deviation measuring apparatus that is capable of measuring the mass deviations of drops discharged from a plurality of drop discharge units in real time and measuring the mass deviations of the drops discharged from the drop discharge units even when the drops have diameters requiring high precision, a drop mass deviation measuring method of the same, a pattern forming system using the same, and a control method of the pattern forming system using the same.
2. Description of the Related Art
A method and apparatus for forming a pattern of a semiconductor circuit or a color filter of a liquid crystal display device leading a display industry generally uses photolithography.
Photolithography includes several operations, such as application, exposure, and development of a process material. Consequently, the photolithography is complicated and needs a long process time. Also, costs required to use a photoresist and a photo mask are high.
In recent years, there have been proposed an inkjet method substituting the photolithography having the above-mentioned drawbacks and a pattern forming system using the inkjet method. The inkjet method and the pattern forming system using the inkjet method form a pattern of a color filter of a liquid crystal display device or a semiconductor circuit.
When the masses of drops discharged from a plurality of drop discharge units are different from one another due to electrical and mechanical causes, however, the pattern of the semiconductor circuit or the pattern of the color filter of the liquid crystal display device may be formed nonuniformly. For this reason, there is a need for an apparatus or method to measure the mass deviation of drops discharged from the drop discharge units to prevent the occurrence of the mass deviation of the drops.
In response to the need, an impact drop analysis method and a drop photograph analysis method may be proposed as the method for measuring the mass deviation of the drops discharged from the drop discharge units.
In the impact drop analysis method, a drop is impacted to an object, such as paper, and the drop impacted on the object is analyzed to measure the mass deviation of drops discharged from a plurality of drop discharge units. In the drop photograph analysis method, the diameters of drops discharged from a plurality of drop discharge units are measured using drop images obtained by passing the drops between a lighting device and a vision camera to measure the mass deviation of the drops.
In the impact drop analysis method, a drop is impacted on an object, and the object on which the drop is impacted is analyzed to measure the mass deviation of the drop. For this reason, it is not easy to acquire the mass deviations of drops discharged from a plurality of drop discharge units in real time using the impact drop analysis method. Consequently, the impact drop analysis method is limited to be applied to a process for forming a pattern of a semiconductor circuit or a pattern of a color filter of a liquid crystal display device. Furthermore, the drop impacted on the object may be absorbed and evaporated, with the result that an error may occur in analyzing the drop impacted on the object.
In the drop photograph analysis method, the diameters of drops discharged from a plurality of drop discharge units are directly measured from the photographed drop images to measure the mass deviations of the drops. Consequently, when the diameters of the drops require high precision, an error may occur in measuring the diameters of the drops.
In addition, a pattern forming system using the impact drop analysis method or drop photograph analysis method and a control method of the pattern forming system have drawbacks in that the time necessary to form a pattern increases, and the system is limited to forming a pattern requiring high precision.